Predictive value and utility of oral steroid testing for treatment of COPD in primary care: the COOPT study

Mucoactive drugs and multiple applications in pulmonary disease therapy

Mucus is a complex polymeric hydrogel that serves as a critical defense in several organs. In the lungs, it provides a formidable barrier against inhaled particles such as microorganisms. In addition, mucus is essential for normal lung physiology, as it promotes immune tolerance and facilitates a normal commensal pulmonary microbiome. Hypersecretion of airway mucus is a characteristic of numerous respiratory diseases, such as Chronic Obstructive Pulmonary Disease (COPD) and Cystic Fibrosis (CF), and creates pulmonary obstruction, limiting the effectiveness of inhaled therapies. Due to those alterations, therapeutic strategies must be optimal to limit airway obstruction and restore pulmonary function. Mucoactive drugs are common therapeutic options and are classified into different groups depending on their modes of action, i.e., expectorants, mucokinetics, mucoregulators and mucolytics. This review focuses on mucoactive drugs and their modes of action. A special focus will be made on two challenging pulmonary pathologies: COPD and CF, and on their clinical studies conducted with mucoactive drugs.

Inhaled corticosteroids versus placebo for stable chronic obstructive pulmonary disease

BACKGROUND

The role of inhaled corticosteroids (ICS) in chronic obstructive pulmonary disease (COPD) has been the subject of much uncertainty. COPD clinical guidelines currently recommend selective use of ICS. ICS are not recommended as monotherapy for people with COPD, and are only given in combination with long-acting bronchodilators due to greater efficacy of combination therapy. Incorporating and critiquing newly published placebo-controlled trials into the monotherapy evidence base may help to resolve ongoing uncertainties and conflicting findings about their role in this population.

OBJECTIVES

To evaluate the benefits and harms of inhaled corticosteroids, used as monotherapy versus placebo, in people with stable COPD, in terms of objective and subjective outcomes.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was October 2022.

SELECTION CRITERIA

We included randomised trials comparing any dose of any type of ICS, given as monotherapy, with a placebo control in people with stable COPD. We excluded studies of less than 12 weeks' duration and studies of populations with known bronchial hyper-responsiveness (BHR) or bronchodilator reversibility.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our a priori primary outcomes were 1. exacerbations of COPD and 2. quality of life. Our secondary outcomes were 3. all-cause mortality, 4. lung function (rate of decline of forced expiratory volume in one second (FEV₁)), 5. rescue bronchodilator use, 6. exercise capacity, 7. pneumonia and 8. adverse events including pneumonia. ]. We used GRADE to assess certainty of evidence.

MAIN RESULTS

Thirty-six primary studies with 23,139 participants met the inclusion criteria. Mean age ranged from 52 to 67 years, and females were 0% to 46% of participants. Studies recruited across the severities of COPD. Seventeen studies were of duration longer than three months and up to six months and 19 studies were of duration longer than six months. We judged the overall risk of bias as low.  Long-term (more than six months) use of ICS as monotherapy reduced the mean rate of exacerbations in those studies where pooling of data was possible (generic inverse variance analysis: rate ratio 0.88 exacerbations per participant per year, 95% confidence interval (CI) 0.82 to 0.94; I² = 48%, 5 studies, 10,097 participants; moderate-certainty evidence; pooled means analysis: mean difference (MD) -0.05 exacerbations per participant per year, 95% CI -0.07 to -0.02; I² = 78%, 5 studies, 10,316 participants; moderate-certainty evidence). ICS slowed the rate of decline in quality of life, as measured by the St George's Respiratory Questionnaire (MD -1.22 units/year, 95% CI -1.83 to -0.60; I² = 0%; 5 studies, 2507 participants; moderate-certainty evidence; minimal clinically importance difference 4 points). There was no evidence of a difference in all-cause mortality in people with COPD (odds ratio (OR) 0.94, 95% CI 0.84 to 1.07; I² = 0%; 10 studies, 16,636 participants; moderate-certainty evidence). Long-term use of ICS  reduced the rate of decline in FEV₁ in people with COPD (generic inverse variance analysis: MD 6.31 mL/year benefit, 95% CI 1.76 to 10.85; I² = 0%; 6 studies, 9829 participants; moderate-certainty evidence; pooled means analysis: 7.28 mL/year, 95% CI 3.21 to 11.35; I² = 0%; 6 studies, 12,502 participants; moderate-certainty evidence).

ADVERSE EVENTS

in the long-term studies, the rate of pneumonia was increased in the ICS group, compared to placebo, in studies that reported pneumonia as an adverse event (OR 1.38, 95% CI 1.02 to 1.88; I² = 55%; 9 studies, 14,831 participants; low-certainty evidence). There was an increased risk of oropharyngeal candidiasis (OR 2.66, 95% CI 1.91 to 3.68; 5547 participants) and hoarseness (OR 1.98, 95% CI 1.44 to 2.74; 3523 participants). The long-term studies that measured bone effects generally showed no major effect on fractures or bone mineral density over three years. We downgraded the certainty of evidence to moderate for imprecision and low for imprecision and inconsistency.

AUTHORS' CONCLUSIONS

This systematic review updates the evidence base for ICS monotherapy with newly published trials to aid the ongoing assessment of their role for people with COPD. Use of ICS alone for COPD likely results in a reduction of exacerbation rates of clinical relevance, probably results in a reduction in the rate of decline of FEV₁ of uncertain clinical relevance and likely results in a small improvement in health-related quality of life not meeting the threshold for a minimally clinically important difference. These potential benefits should be weighed up against adverse events (likely to increase local oropharyngeal adverse effects and may increase the risk of pneumonia) and probably no reduction in mortality. Though not recommended as monotherapy, the probable benefits of ICS highlighted in this review support their continued consideration in combination with long-acting bronchodilators. Future research and evidence syntheses should be focused in that area.

[The place of inhaled corticosteroids in COPD]

INTRODUCTION

Clinical trials have provided some evidence of a favorable effect of inhaled corticosteroids on the frequency of exacerbations and on the quality of life of patients with chronic obstructive pulmonary disease (COPD). In contrast, ICS have little or no impact on lung function decline and on mortality.

STATE OF THE ART

Inhaled corticosteroids are recommended only in a minority of COPD patients, those with severe disease and repeated exacerbations and probably those with the COPD and asthma overlap syndrome. However, surveys indicate that these drugs are inappropriately prescribed in a large population of patients with COPD. Overtreatment with inhaled corticosteroids exposes these patients to an increased risk of potentially severe side-effects such as pneumonia, osteoporosis, and oropharyngeal candidiasis. Moreover, it represents a major waste of health-care spending.

CONCLUSION

Primary care physicians as well as pulmonologists should be better aware of the benefits as well as the side-effects and costs of inhaled corticosteroids.

Diagnosis and pharmacotherapy of stable chronic obstructive pulmonary disease: the finnish guidelines

The Finnish Medical Society Duodecim initiated and managed the update of the Finnish national guideline for chronic obstructive pulmonary disease (COPD). The Finnish COPD guideline was revised to acknowledge the progress in diagnosis and management of COPD. This Finnish COPD guideline in English language is a part of the original guideline and focuses on the diagnosis, assessment and pharmacotherapy of stable COPD. It is intended to be used mainly in primary health care but not forgetting respiratory specialists and other healthcare workers. The new recommendations and statements are based on the best evidence available from the medical literature, other published national guidelines and the GOLD (Global Initiative for Chronic Obstructive Lung Disease) report. This guideline introduces the diagnostic approach, differential diagnostics towards asthma, assessment and treatment strategy to control symptoms and to prevent exacerbations. The pharmacotherapy is based on the symptoms and a clinical phenotype of the individual patient. The guideline defines three clinically relevant phenotypes including the low and high exacerbation risk phenotypes and the neglected asthma-COPD overlap syndrome (ACOS). These clinical phenotypes can help clinicians to identify patients that respond to specific pharmacological interventions. For the low exacerbation risk phenotype, pharmacotherapy with short-acting β2 -agonists (salbutamol, terbutaline) or anticholinergics (ipratropium) or their combination (fenoterol-ipratropium) is recommended in patients with less symptoms. If short-acting bronchodilators are not enough to control symptoms, a long-acting β2 -agonist (formoterol, indacaterol, olodaterol or salmeterol) or a long-acting anticholinergic (muscarinic receptor antagonists; aclidinium, glycopyrronium, tiotropium, umeclidinium) or their combination is recommended. For the high exacerbation risk phenotype, pharmacotherapy with a long-acting anticholinergic or a fixed combination of an inhaled glucocorticoid and a long-acting β2 -agonist (budesonide-formoterol, beclomethasone dipropionate-formoterol, fluticasone propionate-salmeterol or fluticasone furoate-vilanterol) is recommended as a first choice. Other treatment options for this phenotype include combination of long-acting bronchodilators given from separate inhalers or as a fixed combination (glycopyrronium-indacaterol or umeclidinium-vilanterol) or a triple combination of an inhaled glucocorticoid, a long-acting β2 -agonist and a long-acting anticholinergic. If the patient has severe-to-very severe COPD (FEV1  < 50% predicted), chronic bronchitis and frequent exacerbations despite long-acting bronchodilators, the pharmacotherapy may include also roflumilast. ACOS is a phenotype of COPD in which there are features that comply with both asthma and COPD. Patients belonging to this phenotype have usually been excluded from studies evaluating the effects of drugs both in asthma and in COPD. Thus, evidence-based recommendation of treatment cannot be given. The treatment should cover both diseases. Generally, the therapy should include at least inhaled glucocorticoids (beclomethasone dipropionate, budesonide, ciclesonide, fluticasone furoate, fluticasone propionate or mometasone) combined with a long-acting bronchodilator (β2 -agonist or anticholinergic or both).

Collaborative self-management and behavioral change

Behavioral change is critical for improving health outcomes in patients with chronic obstructive pulmonary disease. An educational approach alone is insufficient; changes in behavior, especially the acquisition of self-care skills, are also required. There is mounting evidence that embedding collaborative self-management (CSM) within existing health care systems provides an effective model to meet these needs. CSM should be integrated with pulmonary rehabilitation programs, one of the main goals of which is to induce long-term changes in behavior. More research is needed to evaluate the effectiveness of assimilating CSM into primary care, patient-centered medical homes, and palliative care teams.

Long-acting inhaled therapy (beta-agonists, anticholinergics and steroids) for COPD: a network meta-analysis

BACKGROUND

Pharmacological therapy for chronic obstructive pulmonary disease (COPD) is aimed at relieving symptoms, improving quality of life and preventing or treating exacerbations.Treatment tends to begin with one inhaler, and additional therapies are introduced as necessary. For persistent or worsening symptoms, long-acting inhaled therapies taken once or twice daily are preferred over short-acting inhalers. Several Cochrane reviews have looked at the risks and benefits of specific long-acting inhaled therapies compared with placebo or other treatments. However for patients and clinicians, it is important to understand the merits of these treatments relative to each other, and whether a particular class of inhaled therapies is more beneficial than the others.

OBJECTIVES

To assess the efficacy of treatment options for patients whose chronic obstructive pulmonary disease cannot be controlled by short-acting therapies alone. The review will not look at combination therapies usually considered later in the course of the disease.As part of this network meta-analysis, we will address the following issues.1. How does long-term efficacy compare between different pharmacological treatments for COPD?2. Are there limitations in the current evidence base that may compromise the conclusions drawn by this network meta-analysis? If so, what are the implications for future research?

SEARCH METHODS

We identified randomised controlled trials (RCTs) in existing Cochrane reviews by searching the Cochrane Database of Systematic Reviews (CDSR). In addition, we ran a comprehensive citation search on the Cochrane Airways Group Register of trials (CAGR) and checked manufacturer websites and reference lists of other reviews. The most recent searches were conducted in September 2013.

SELECTION CRITERIA

We included parallel-group RCTs of at least 6 months' duration recruiting people with COPD. Studies were included if they compared any of the following treatments versus any other: long-acting beta2-agonists (LABAs; formoterol, indacaterol, salmeterol); long-acting muscarinic antagonists (LAMAs; aclidinium, glycopyrronium, tiotropium); inhaled corticosteroids (ICSs; budesonide, fluticasone, mometasone); combination long-acting beta2-agonist (LABA) and inhaled corticosteroid (LABA/ICS) (formoterol/budesonide, formoterol/mometasone, salmeterol/fluticasone); and placebo.

DATA COLLECTION AND ANALYSIS

We conducted a network meta-analysis using Markov chain Monte Carlo methods for two efficacy outcomes: St George's Respiratory Questionnaire (SGRQ) total score and trough forced expiratory volume in one second (FEV1). We modelled the relative effectiveness of any two treatments as a function of each treatment relative to the reference treatment (placebo). We assumed that treatment effects were similar within treatment classes (LAMA, LABA, ICS, LABA/ICS). We present estimates of class effects, variability between treatments within each class and individual treatment effects compared with every other.To justify the analyses, we assessed the trials for clinical and methodological transitivity across comparisons. We tested the robustness of our analyses by performing sensitivity analyses for lack of blinding and by considering six- and 12-month data separately.

MAIN RESULTS

We identified 71 RCTs randomly assigning 73,062 people with COPD to 184 treatment arms of interest. Trials were similar with regards to methodology, inclusion and exclusion criteria and key baseline characteristics. Participants were more often male, aged in their mid sixties, with FEV1 predicted normal between 40% and 50% and with substantial smoking histories (40+ pack-years). The risk of bias was generally low, although missing information made it hard to judge risk of selection bias and selective outcome reporting. Fixed effects were used for SGRQ analyses, and random effects for Trough FEV1 analyses, based on model fit statistics and deviance information criteria (DIC). SGRQ SGRQ data were available in 42 studies (n = 54,613). At six months, 39 pairwise comparisons were made between 18 treatments in 25 studies (n = 27,024). Combination LABA/ICS was the highest ranked intervention, with a mean improvement over placebo of -3.89 units at six months (95% credible interval (CrI) -4.70 to -2.97) and -3.60 at 12 months (95% CrI -4.63 to -2.34). LAMAs and LABAs were ranked second and third at six months, with mean differences of -2.63 (95% CrI -3.53 to -1.97) and -2.29 (95% CrI -3.18 to -1.53), respectively. Inhaled corticosteroids were ranked fourth (MD -2.00, 95% CrI -3.06 to -0.87). Class differences between LABA, LAMA and ICS were less prominent at 12 months. Indacaterol and aclidinium were ranked somewhat higher than other members of their classes, and formoterol 12 mcg, budesonide 400 mcg and formoterol/mometasone combination were ranked lower within their classes. There was considerable overlap in credible intervals and rankings for both classes and individual treatments. Trough FEV1 Trough FEV1 data were available in 46 studies (n = 47,409). At six months, 41 pairwise comparisons were made between 20 treatments in 31 studies (n = 29,271). As for SGRQ, combination LABA/ICS was the highest ranked class, with a mean improvement over placebo of 133.3 mL at six months (95% CrI 100.6 to 164.0) and slightly less at 12 months (mean difference (MD) 100, 95% CrI 55.5 to 140.1). LAMAs (MD 103.5, 95% CrI 81.8 to 124.9) and LABAs (MD 99.4, 95% CrI 72.0 to 127.8) showed roughly equivalent results at six months, and ICSs were the fourth ranked class (MD 65.4, 95% CrI 33.1 to 96.9). As with SGRQ, initial differences between classes were not so prominent at 12 months. Indacaterol and salmeterol/fluticasone were ranked slightly better than others in their class, and formoterol 12, aclidinium, budesonide and formoterol/budesonide combination were ranked lower within their classes. All credible intervals for individual rankings were wide.

AUTHORS' CONCLUSIONS

This network meta-analysis compares four different classes of long-acting inhalers for people with COPD who need more than short-acting bronchodilators. Quality of life and lung function were improved most on combination inhalers (LABA and ICS) and least on ICS alone at 6 and at 12 months. Overall LAMA and LABA inhalers had similar effects, particularly at 12 months. The network has demonstrated the benefit of ICS when added to LABA for these outcomes in participants who largely had an FEV1 that was less than 50% predicted, but the additional expense of combination inhalers and any potential for increased adverse events (which has been established by other reviews) require consideration. Our findings are in keeping with current National Institute for Health and Care Excellence (NICE) guidelines.

Inhaled steroids and risk of pneumonia for chronic obstructive pulmonary disease

BACKGROUND

Inhaled corticosteroids (ICS) are anti-inflammatory drugs that have proven benefits for people with worsening symptoms of chronic obstructive pulmonary disease (COPD) and repeated exacerbations. They are commonly used as combination inhalers with long-acting beta2-agonists (LABA) to reduce exacerbation rates and all-cause mortality, and to improve lung function and quality of life. The most common combinations of ICS and LABA used in combination inhalers are fluticasone and salmeterol, budesonide and formoterol and a new formulation of fluticasone in combination with vilanterol, which is now available. ICS have been associated with increased risk of pneumonia, but the magnitude of risk and how this compares with different ICS remain unclear. Recent reviews conducted to address their safety have not compared the relative safety of these two drugs when used alone or in combination with LABA.

OBJECTIVES

To assess the risk of pneumonia associated with the use of fluticasone and budesonide for COPD.

SEARCH METHODS

We identified trials from the Cochrane Airways Group Specialised Register of trials (CAGR), clinicaltrials.gov, reference lists of existing systematic reviews and manufacturer websites. The most recent searches were conducted in September 2013.

SELECTION CRITERIA

We included parallel-group randomised controlled trials (RCTs) of at least 12 weeks' duration. Studies were included if they compared the ICS budesonide or fluticasone versus placebo, or either ICS in combination with a LABA versus the same LABA as monotherapy for people with COPD.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted study characteristics, numerical data and risk of bias information for each included study.We looked at direct comparisons of ICS versus placebo separately from comparisons of ICS/LABA versus LABA for all outcomes, and we combined these with subgroups when no important heterogeneity was noted. After assessing for transitivity, we conducted an indirect comparison to compare budesonide versus fluticasone monotherapy, but we could not do the same for the combination therapies because of systematic differences between the budesonide and fluticasone combination data sets.When appropriate, we explored the effects of ICS dose, duration of ICS therapy and baseline severity on the primary outcome. Findings of all outcomes are presented in 'Summary of findings' tables using GRADEPro.

MAIN RESULTS

We found 43 studies that met the inclusion criteria, and more evidence was provided for fluticasone (26 studies; n = 21,247) than for budesonide (17 studies; n = 10,150). Evidence from the budesonide studies was more inconsistent and less precise, and the studies were shorter. The populations within studies were more often male with a mean age of around 63, mean pack-years smoked over 40 and mean predicted forced expiratory volume of one second (FEV1) less than 50%.High or uneven dropout was considered a high risk of bias in almost 40% of the trials, but conclusions for the primary outcome did not change when the trials at high risk of bias were removed in a sensitivity analysis.Fluticasone increased non-fatal serious adverse pneumonia events (requiring hospital admission) (odds ratio (OR) 1.78, 95% confidence interval (CI) 1.50 to 2.12; 18 more per 1000 treated over 18 months; high quality), and no evidence suggested that this outcome was reduced by delivering it in combination with salmeterol or vilanterol (subgroup differences: I(2) = 0%, P value 0.51), or that different doses, trial duration or baseline severity significantly affected the estimate. Budesonide also increased non-fatal serious adverse pneumonia events compared with placebo, but the effect was less precise and was based on shorter trials (OR 1.62, 95% CI 1.00 to 2.62; six more per 1000 treated over nine months; moderate quality). Some of the variation in the budesonide data could be explained by a significant difference between the two commonly used doses: 640 mcg was associated with a larger effect than 320 mcg relative to placebo (subgroup differences: I(2) = 74%, P value 0.05).An indirect comparison of budesonide versus fluticasone monotherapy revealed no significant differences with respect to serious adverse events (pneumonia-related or all-cause) or mortality. The risk of any pneumonia event (i.e. less serious cases treated in the community) was higher with fluticasone than with budesonide (OR 1.86, 95% CI 1.04 to 3.34); this was the only significant difference reported between the two drugs. However, this finding should be interpreted with caution because of possible differences in the assignment of pneumonia diagnosis, and because no trials directly compared the two drugs.No significant difference in overall mortality rates was observed between either of the inhaled steroids and the control interventions (both high-quality evidence), and pneumonia-related deaths were too rare to permit conclusions to be drawn.

AUTHORS' CONCLUSIONS

Budesonide and fluticasone, delivered alone or in combination with a LABA, are associated with increased risk of serious adverse pneumonia events, but neither significantly affected mortality compared with controls. The safety concerns highlighted in this review should be balanced with recent cohort data and established randomised evidence of efficacy regarding exacerbations and quality of life. Comparison of the two drugs revealed no statistically significant difference in serious pneumonias, mortality or serious adverse events. Fluticasone was associated with higher risk of any pneumonia when compared with budesonide (i.e. less serious cases dealt with in the community), but variation in the definitions used by the respective manufacturers is a potential confounding factor in their comparison.Primary research should accurately measure pneumonia outcomes and should clarify both the definition and the method of diagnosis used, especially for new formulations such as fluticasone furoate, for which little evidence of the associated pneumonia risk is currently available. Similarly, systematic reviews and cohorts should address the reliability of assigning 'pneumonia' as an adverse event or cause of death and should determine how this affects the applicability of findings.

Inhaled corticosteroids for stable chronic obstructive pulmonary disease

BACKGROUND

The role of inhaled corticosteroids (ICS) in chronic obstructive pulmonary disease (COPD) has been the subject of much controversy. Major international guidelines recommend selective use of ICS. Recently published meta-analyses have reported conflicting findings on the effects of inhaled steroid therapy in COPD.

OBJECTIVES

To determine the efficacy and safety of inhaled corticosteroids in stable patients with COPD, in terms of objective and subjective outcomes.

SEARCH METHODS

A pre-defined search strategy was used to search the Cochrane Airways Group Specialised Register for relevant literature. Searches are current as of July 2011.

SELECTION CRITERIA

We included randomised trials comparing any dose of any type of inhaled steroid with a placebo control in patients with COPD. Acute bronchodilator reversibility to short-term beta(2)-agonists and bronchial hyper-responsiveness were not exclusion criteria. The a priori primary outcome was change in lung function. We also analysed data on mortality, exacerbations, quality of life and symptoms, rescue bronchodilator use, exercise capacity, biomarkers and safety.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We contacted study authors for additional information. We collected adverse effects information from the trials.

MAIN RESULTS

Fifty-five primary studies with 16,154 participants met the inclusion criteria. Long-term use of ICS (more than six months) did not consistently reduce the rate of decline in forced expiratory volume in one second (FEV(1)) in COPD patients (generic inverse variance analysis: mean difference (MD) 5.80 mL/year with ICS over placebo, 95% confidence interval (CI) -0.28 to 11.88, 2333 participants; pooled means analysis: 6.88 mL/year, 95% CI 1.80 to 11.96, 4823 participants), although one major trial demonstrated a statistically significant difference. There was no statistically significant effect on mortality in COPD patients (odds ratio (OR) 0.98, 95% CI 0.83 to 1.16, 8390 participants). Long-term use of ICS reduced the mean rate of exacerbations in those studies where pooling of data was possible (generic inverse variance analysis: MD -0.26 exacerbations per patient per year, 95% CI -0.37 to -0.14, 2586 participants; pooled means analysis: MD -0.19 exacerbations per patient per year, 95% CI -0.30 to -0.08, 2253 participants). ICS slowed the rate of decline in quality of life, as measured by the St George's Respiratory Questionnaire (MD -1.22 units/year, 95% CI -1.83 to -0.60, 2507 participants). Response to ICS was not predicted by oral steroid response, bronchodilator reversibility or bronchial hyper-responsiveness in COPD patients. There was an increased risk of oropharyngeal candidiasis (OR 2.65, 95% CI 2.03 to 3.46, 5586 participants) and hoarseness. In the long-term studies, the rate of pneumonia was increased in the ICS group compared to placebo, in studies that reported pneumonia as an adverse event (OR 1.56, 95% CI 1.30 to 1.86, 6235 participants). The long-term studies that measured bone effects generally showed no major effect on fractures and bone mineral density over three years.

AUTHORS' CONCLUSIONS

Patients and clinicians should balance the potential benefits of inhaled steroids in COPD (reduced rate of exacerbations, reduced rate of decline in quality of life and possibly reduced rate of decline in FEV(1)) against the potential side effects (oropharyngeal candidiasis and hoarseness, and risk of pneumonia).

Diagnostic value of oral prednisolone test for chronic obstructive pulmonary disorders

PURPOSE

We wanted to determine the diagnostic value of an oral prednisolone test for chronic obstructive pulmonary disorders.

METHODS

Two hundred thirty-three patients with cough for longer than 14 days, without known chronic obstructive pulmonary disease (COPD) or asthma, participated in a diagnostic study in Dutch primary care between 2006 and 2009. These patients used a 14-day prednisolone test of 30 mg/d and recorded before-after bronchodilator measurements of forced expiratory volume in 1 second (FEV(1)). An expert panel determined the presence or absence of COPD and asthma based on an extensive diagnostic workup. The proportion of responders to the prednisolone test (increased FEV(1) exceeding 200 mL or 12% of baseline) per diagnosis group was compared, and the diagnostic value of the test was quantified by logistic regression and analysis of the area under the receiver operating characteristic curve (ROC area).

RESULTS

In patients with COPD, 23% (14 of 61) responded to the test; in patients with asthma 4% (1 of 25) responded; in patients with asthma and COPD, 7% (1 of 14) responded; and in those without asthma or COPD, 11% (14 of 133) responded. Being a responder was, unexpectedly, associated with COPD (OR = 2.4; 95% confidence interval [CI], 1.1-5.2). After multivariate analysis, adjusting for age, sex, and smoking, the OR = 2.0 (95% CI, 0.8-5.0) and the ROC area did not increase (0.78; 95% CI, 0.72-0.85 vs 0.79; 95% CI, 0.72-0.85).

CONCLUSION

A response to a prednisolone test was suggestive of COPD, but added no diagnostic value to more easily obtainable characteristics.

Systematic review of the evidence relating FEV1 decline to giving up smoking

BACKGROUND

The rate of forced expiratory volume in 1 second (FEV1) decline ("beta") is a marker of chronic obstructive pulmonary disease risk. The reduction in beta after quitting smoking is an upper limit for the reduction achievable from switching to novel nicotine delivery products. We review available evidence to estimate this reduction and quantify the relationship of smoking to beta.

METHODS

Studies were identified, in healthy individuals or patients with respiratory disease, that provided data on beta over at least 2 years of follow-up, separately for those who gave up smoking and other smoking groups. Publications to June 2010 were considered. Independent beta estimates were derived for four main smoking groups: never smokers, ex-smokers (before baseline), quitters (during follow-up) and continuing smokers. Unweighted and inverse variance-weighted regression analyses compared betas in the smoking groups, and in continuing smokers by amount smoked, and estimated whether beta or beta differences between smoking groups varied by age, sex and other factors.

RESULTS

Forty-seven studies had relevant data, 28 for both sexes and 19 for males. Sixteen studies started before 1970. Mean follow-up was 11 years. On the basis of weighted analysis of 303 betas for the four smoking groups, never smokers had a beta 10.8 mL/yr (95% confidence interval (CI), 8.9 to 12.8) less than continuing smokers. Betas for ex-smokers were 12.4 mL/yr (95% CI, 10.1 to 14.7) less than for continuing smokers, and for quitters, 8.5 mL/yr (95% CI, 5.6 to 11.4) less. These betas were similar to that for never smokers. In continuing smokers, beta increased 0.33 mL/yr per cigarette/day. Beta differences between continuing smokers and those who gave up were greater in patients with respiratory disease or with reduced baseline lung function, but were not clearly related to age or sex.

CONCLUSION

The available data have numerous limitations, but clearly show that continuing smokers have a beta that is dose-related and over 10 mL/yr greater than in never smokers, ex-smokers or quitters. The greater decline in those with respiratory disease or reduced lung function is consistent with some smokers having a more rapid rate of FEV1 decline. These results help in designing studies comparing continuing smokers of conventional cigarettes and switchers to novel products.